Replace all binary SDK libc functions with newlib

Adds a new build step to remove the SDK object files listed in
<libname>.remove.

Closes #1.

FreeRTOS/Source/portable/esp8266/sdk_compat.c

@@ -1,14 +0,0 @@
-/*
- * Wrappers for functions called by binary espressif libraries
- *
- * Part of esp-open-rtos
- * Copyright (C) 2015 Superhouse Automation Pty Ltd
- * BSD Licensed as described in the file LICENSE
- */
-#include <stdlib.h>
-#include <string.h>
-#include "FreeRTOS.h"
-
-void *zalloc(size_t nbytes) {
-    return calloc(1, nbytes);
-}

common.mk

@@ -65,7 +65,7 @@ COMPONENTS     ?= core FreeRTOS lwip axtls
 SDK_LIBS		?= main net80211 phy pp wpa
 
 # open source libraries linked in
-LIBS ?= gcc hal
+LIBS ?= gcc hal cirom
 
 # Note: this isn't overridable without a not-yet-merged patch to esptool
 ENTRY_SYMBOL = call_user_start
@@ -186,35 +186,50 @@ endef
 
 ## Linking rules for SDK libraries
 ## SDK libraries are preprocessed to:
+# - remove object files named in <libname>.remove
 # - prefix all defined symbols with 'sdk_'
 # - weaken all global symbols so they can be overriden from the open SDK side
-
-# SDK binary libraries are preprocessed into build/lib
+#
+# SDK binary libraries are preprocessed into build/sdklib
 SDK_PROCESSED_LIBS = $(addsuffix .a,$(addprefix $(BUILD_DIR)sdklib/lib,$(SDK_LIBS)))
 
-# Make rule for preprocessing each SDK library
-#
-$(BUILD_DIR)sdklib/%.a: $(ROOT)lib/%.a $(BUILD_DIR)sdklib/allsymbols.rename
-	$(vecho) "Pre-processing SDK library $< -> $@"
-	$(Q) $(OBJCOPY) --redefine-syms $(word 2,$^) --weaken $< $@
+# Make rules for preprocessing each SDK library
 
+# hacky, but prevents confusing error messages if one of these files disappears
+$(ROOT)lib/%.remove:
+	touch $@
 
-# Generate a regex to match symbols we don't want to rename, by parsing
-# a list of symbol names
+# Remove comment lines from <libname>.remove files
+$(BUILD_DIR)sdklib/%.remove: $(ROOT)lib/%.remove | $(BUILD_DIR)sdklib
+	$(Q) grep -v "^#" $< | cat > $@
+
+# Stage 1: remove unwanted object files listed in <libname>.remove alongside each library
+$(BUILD_DIR)sdklib/%_stage1.a: $(ROOT)lib/%.a $(BUILD_DIR)sdklib/%.remove | $(BUILD_DIR)sdklib
+	@echo "SDK processing stage 1: Removing unwanted objects from $<"
+	$(Q) cat $< > $@
+	$(Q) $(AR) d $@ @$(word 2,$^)
+
+# Generate a regex to match symbols we don't want to rename, listed in
+# symbols_norename.txt
 $(BUILD_DIR)sdklib/norename.match: $(ROOT)lib/symbols_norename.txt | $(BUILD_DIR)sdklib
-	grep -v "^#" $< | sed ':begin;$!N;s/\n/\\|/;tbegin' > $@
+	cat $< | grep -v "^#" | sed ':begin;$!N;s/\n/\\|/;tbegin' > $@
 
-# Generate list of defined symbols to rename from a single library. Uses grep & sed.
-$(BUILD_DIR)sdklib/%.rename: $(ROOT)lib/%.a $(BUILD_DIR)sdklib/norename.match
-	$(vecho) "Building symbol list for $< -> $@"
+# Stage 2: Build a list of defined symbols per library, renamed with sdk_ prefix
+$(BUILD_DIR)sdklib/%.rename: $(BUILD_DIR)sdklib/%_stage1.a $(BUILD_DIR)sdklib/norename.match
+	@echo "SDK processing stage 2: Building symbol list for $< -> $@"
 	$(Q) $(OBJDUMP) -t $< | grep ' g ' \
 		| sed -r 's/^.+ ([^ ]+)$$/\1 sdk_\1/' \
 		| grep -v `cat $(BUILD_DIR)sdklib/norename.match` > $@
 
-# Build master list of all SDK-defined symbols to rename
+# Build a master list of all SDK-defined symbols to rename across all libraries
 $(BUILD_DIR)sdklib/allsymbols.rename: $(patsubst %.a,%.rename,$(SDK_PROCESSED_LIBS))
 	cat $^ > $@
 
+# Stage 3: Redefine all SDK symbols as sdk_, weaken all symbols.
+$(BUILD_DIR)sdklib/%.a: $(BUILD_DIR)sdklib/%_stage1.a $(BUILD_DIR)sdklib/allsymbols.rename
+	@echo "SDK processing stage 3: Renaming symbols in SDK library $< -> $@"
+	$(Q) $(OBJCOPY) --redefine-syms $(word 2,$^) --weaken $< $@
+
 # include "dummy component" for the 'program' object files, defined in the Makefile
 PROGRAM_SRC_DIR ?= $(PROGRAM_DIR)
 PROGRAM_ROOT ?= $(PROGRAM_DIR)
@@ -227,7 +242,7 @@ $(foreach component,$(COMPONENTS), $(eval include $(ROOT)$(component)/component.
 # final linking step to produce .elf
 $(PROGRAM_OUT): $(COMPONENT_ARS) $(SDK_PROCESSED_LIBS) $(LINKER_SCRIPTS)
 	$(vecho) "LD $@"
-	$(Q) $(LD) $(LDFLAGS) -Wl,--start-group $(SDK_LIB_ARGS) $(LIB_ARGS) $(COMPONENT_ARS) -Wl,--end-group -o $@
+	$(Q) $(LD) $(LDFLAGS) -Wl,--start-group $(LIB_ARGS) $(SDK_LIB_ARGS) $(COMPONENT_ARS) -Wl,--end-group -o $@
 
 $(BUILD_DIR) $(FW_BASE) $(BUILD_DIR)sdklib:
 	$(Q) mkdir -p $@

core/sdk_compat.c

@@ -0,0 +1,28 @@
+/*
+ * Wrappers for functions called by binary espressif libraries
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2015 Superhouse Automation Pty Ltd
+ * BSD Licensed as described in the file LICENSE
+ */
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+void *zalloc(size_t nbytes)
+{
+    return calloc(1, nbytes);
+}
+
+/* this is currently just a stub to see where in the SDK it gets
+   called, and with what arguments...
+
+   In the binary SDK printf & ets_printf are aliased together, most
+   references appear to be to printf but libphy, libwpa & libnet80211
+   all call ets_printf sometimes... Seems to not be in common code
+   paths, haven't investigated exactly where.
+*/
+int ets_printf(const char *format, ...)  {
+    return printf("ets_printf format=%s\r\n", format);
+}
+

examples/http_get/main.c

@@ -7,6 +7,8 @@
 #include "espressif/esp_common.h"
 #include "espressif/sdk_private.h"
 
+#include <string.h>
+
 #include "FreeRTOS.h"
 #include "task.h"
 

examples/http_get_ssl/main.c

@@ -9,6 +9,8 @@
 #include "espressif/esp_common.h"
 #include "espressif/sdk_private.h"
 
+#include <string.h>
+
 #include "FreeRTOS.h"
 #include "task.h"
 

examples/tests/hmac_test_vectors/main.c

@@ -12,6 +12,8 @@
 #include "FreeRTOS.h"
 #include "ssl.h"
 
+#include <string.h>
+
 struct test_vector {
     const uint8_t *key;
     const uint8_t key_len;

include/espressif/esp_common.h

@@ -10,7 +10,6 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-#include "esp_libc.h"
 #include "esp_misc.h"
 #include "esp_wifi.h"
 #include "esp_softap.h"

include/espressif/esp_libc.h

@@ -1,64 +0,0 @@
-/*
- *  Copyright (c) 2010 - 2011 Espressif System
- *
- */
-
-#ifndef __ESP_LIBC_H__
-#define __ESP_LIBC_H__
-
-char *strcpy(char *dst, const char *src);
-char *strncpy(char *dst, const char *src, size_t n);
-int strcmp(const char *s1, const char *s2);
-int strncmp(const char *s1, const char *s2, size_t n);
-size_t strlen(const char *s);
-char *strstr(const char *s1, const char *s2);
-char *strcat(char *dst, const char *src);
-char *strncat(char *dst, const char *src, size_t count);
-size_t strspn(const char *s, const char *accept);
-size_t strcspn(const char *s, const char *reject);
-char *strtok_r(char *s, const char *delim, char **ptrptr);
-char *strtok(char *s, const char *delim);
-char *strrchr(const char *s, int c);
-char *strdup(const char *s);
-char *strchr(const char *s, int c);
-long strtol(const char *str, char **endptr, int base);
-
-void bzero(void *s, size_t n);
-
-void *memcpy(void *dst, const void *src, size_t n);
-void *memset(void *dst, int c, size_t n);
-int memcmp(const void *m1, const void *m2, size_t n);
-void *memmove(void *dst, const void *src, size_t n);
-
-int rand_r(unsigned int *seed);
-int rand(void);
-void srand(unsigned int i);
-
-int printf(const char *format, ...);
-int sprintf(char *out, const char *format, ...);
-int snprintf(char *buf, unsigned int count, const char *format, ...);
-int puts(const char *str);
-int putchar(int c);
-
-void *malloc(size_t n);
-void free(void *p);
-void *calloc(size_t c, size_t n);
-void *zalloc(size_t n);
-void *realloc(void *p, size_t n);
-
-int atoi(const char *s);
-long atol(const char *s);
-
-/* NOTE: don't use printf_opt in irq handler, for test */
-#define printf_opt(fmt, ...) do {	\
-	static const char flash_str[] ICACHE_RODATA_ATTR = fmt;	\
-	printf(flash_str, ##__VA_ARGS__);	\
-	} while(0)
-
-/* NOTE: don't use printf_opt in irq handler, for test */
-#define sprintf_opt(out, fmt, ...) do {	\
-	static const char flash_str[] ICACHE_RODATA_ATTR = fmt;	\
-	sprintf(out, flash_str, ##__VA_ARGS__);	\
-	} while(0)
-
-#endif /* __LIBC_H__ */

lib/libmain.remove

@@ -0,0 +1,3 @@
+# Object files to be removed from libmain
+printf-stdarg.o
+libc.o